A retrospective comparison of three modalities for vestibuloplasty in the posterior mandible: apically positioned flap only vs. free gingival graft vs. collagen matrix

Objectives: This work aimed to comparatively evaluate the three modalities of vestibuloplasty around implants in the posterior mandible.

Materials and methods: Forty patients who presented with a shallow vestibule and insufficient keratinized gingiva were divided into three groups: apically positioned flap only (APF group), APF with free gingival graft (FGG group), and APF with collagen matrix (CM group). The width of KT was measured at baseline, immediately after surgery (T0), and 6 months (T6) and 12 months after surgery (T12). An esthetic evaluation (color match, contour, and texture) was conducted.

Results: Most of the shrinkage occurred within 6 months. The FGG group demonstrated less shrinkage of KT up to 12 months compared to the APF and CM groups. The APF and CM groups exhibited a prolonged and similar rate of shrinkage. The APF and CM groups also showed significantly better esthetic profiles.

Conclusions: Within the limitations of the present study, FGG may be the most predictable modality for increasing KT in the posterior mandible, but it should be emphasized that the posterior mandible does not require high esthetics.

Clinical relevance: The effect of apically positioned flap and collagen matrix may be diminished by several factors in posterior mandible, such as low vestibule and high muscle pull. For increasing the dimension of keratinized tissue in posterior mandible, conventional free gingival graft may be more predictable compared to other options.